The invention was made in the course of work under grants from the Department of Health, Education and Welfare.
The invention relates generally to heart assist devices and, more particularly, to an auxiliary ventricle which augments the circulation of the blood through the body. A dynamic aortic patch is a mechanical auxiliary ventricle which is surgically implanted in the descending thoracic aorta and which provides a movable vessel wall at the location of the implantation. The patch is systematically inflated and deflated by the application of fluidic pressure to move the wall of the patch and thus generate pressure waves in the bloodstream. These pressure waves support the heart by augmenting the circulation of blood thus increasing coronary flow.
A dynamic aortic patch is a permanently implanted circulatory assist device intended for use in supporting the circulation of patients whose cardiac action is chronically inadequate and cannot be restored by established medical or surgical techniques. It is designed to support the heart by augmenting the circulation of blood to the coronary vessels and peripheral vasculature.
The original dynamic aortic patch included a flexible bladder to which was cemented a Dacron covering sheet which was non-thrombogenic. The use of the initial dynamic aortic patch was published in "Transactions of the American Society of Artificial Internal Organs," Volume XVIII, Page 159 (1972), and in "Transplant Proceedings," Volume III, p. 1459 (1971).
The dynamic aortic patch as previously published included a flexible hollow tube connected to the bladder. The bladder was systematically inflated and deflated by the introduction of fluid pressure, such as compressed gas, through the tube and into the bladder. During the implantation of the bladder extracorporeal bypass was necessary.
Various problems were noted with the original dynamic aortic patch. At first, since the bladder and cover were cemented together prior to implantation, there was always the inherent danger of damaging the bladder by puncturing it during suturing. This, of course, significantly increased the time necessary to implant the apparatus and hence the time that the patient was on a heart-lung machine.
Second, if it was necessary to later replace the bladder component because of normal wear, the entire apparatus had to be removed and a new patch sutured in place. This, again, required extracorporeal bypass.
Hence, the present invention overcomes these problems by providing an improved dynamic aortic patch having none of these shortcomings.